Retinal disorders

Gene: BBIP1

Green List (high evidence)

Comment on list classification: There are 3 individuals reported in literature with biallelic BBIP1 variants and Bardet-Biedl syndrome. Retinal degeneration was confirmed in 2 unrelated patients. Moreover, zebrafish bbip1 knockdown resulted in abnormal retinal development. Hence, this gene should be promoted to Green at the next update.

Created: 27 Mar 2026, 3:50 p.m. | Last Modified: 27 Mar 2026, 3:50 p.m.

Panel Version: 8.104

PMID: 37239474 Nawaz et al., 2023
Homozygous nonsense mutation (c.160A>T; p.Lys54Ter) in the BBIP1 (NM_001195306.1) gene in family B (Pakistani origin). Affected individual with suspected Bardet–Biedl Syndrome presented with polydactyly, retinal degeneration, obesity, hypogonadism, and renal abnormality. No ID/DD seen.

PMID: 32055034 Shamseldin et al., 2020
A patient with classical BBS (18DG0012) harboured a homozygous novel variant NM_001195305.1:c.38–6T > C (aberrant splicing confirmed by RT-PCR with 86% NMD. OMIM states "The patient was reported to have classic features of BBS, with obesity, impaired intellectual development, polydactyly, and end-stage retinitis pigmentosa." but I was not able to verify this in the primary publication.

PMID: 24026985 Scheidecker et al., 2014
Italian BBS patient with a homozygous stop mutation (NM_001195306: c.173T>G, p.Leu58*) in the BBIP1 gene. No BBIP1 protein could be detected in fibroblasts from the patient. He presented with retinitis pigmentosa, obesity, kidney failure, cognitive disability, and brachydactyly. He was diagnosed as affected with BBS at 49 years old. He presented an end-stage renal failure 4 years after the diagnosis.
Functional evidence: morpholino knockdown of bbip1 in zebrafish leads to ciliopathy phenotypes: 20% of morphants present with situs inversus; morphants showed abnormal retinal development, and bilateral cystic dilations of the pronephros (an equivalent structure to the human kidney).

Created: 27 Mar 2026, 3:47 p.m. | Last Modified: 27 Mar 2026, 3:47 p.m.

Panel Version: 8.103

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Bardet-Biedl syndrome 18, OMIM:615995

Publications

• 24026985
• 32055034
• 37239474

I don't know

single report only

Created: 30 Aug 2019, 2:12 p.m. | Last Modified: 30 Aug 2019, 2:12 p.m.

Panel Version: 1.159

Red List (low evidence)

This gene is on the Manchester Genetic Retinal Degeneration Conditions panel (covers known genes for isolated progessive retinal degeneration, Leber congenital amaurosis, macular dystrophy, achromatopsia, congenital stationary night blindness as well as the two most common causes of syndromic blindess Usher and Bardet-Biedl syndromes and additional syndromes including Joubert, Senior-Loken, and Cohen syndrome.

Created: 2 Jun 2016, 8:05 a.m.

Seems to only be one case report in the literature. Is rated red on the Bardet Biedl version 1 panel.

Created: 1 Jun 2016, 9:49 a.m.